/* 计算器样式 */
.calculator {
    max-width: 320px;
    margin: 0 auto;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    background: #f5f5f5;
}

.calculator-display {
    padding: 15px;
    background: #2c3e50;
    text-align: right;
}

.calculator-display input {
    width: 100%;
    padding: 10px;
    font-size: 2rem;
    border: none;
    background: transparent;
    color: white;
    text-align: right;
}

.calculator-keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1px;
    background: #ddd;
}

.calc-btn {
    padding: 20px;
    font-size: 1.2rem;
    border: none;
    background: white;
    cursor: pointer;
    transition: background 0.2s;
}

.calc-btn:hover {
    background: #f0f0f0;
}

.calc-btn:active {
    background: #e0e0e0;
}

.calc-btn.operator {
    background: #f0f0f0;
    font-weight: bold;
}

.calc-btn[data-value="="] {
    background: #3498db;
    color: white;
}

.calc-btn[data-value="C"],
.calc-btn[data-value="CE"] {
    background: #e74c3c;
    color: white;
}

#calcDisplay {
    width: 100%;
}